Though the above link did not confirm it, apparently this or a route nearby may be designated as WIS 318. The route linked above is CTH TT from I-94 south to CTH D plus new ROW to WIS 59. The city and state are splitting costs on it and it relates to a "TEMP US 18" which was added along WIS 83 and I-94 to attempt to reroute US-18 traffic around the project.

(For facebook users - this was posted (https://www.facebook.com/photo.php?fbid=10212527583039364&set=gm.10155083192942344&type=3) to the "Traffic Signals and Highway Signs" group, and the camera looks to be facing northeast at the interchange of I-94 and CTH G which happens to be the northern end of the project.

General location of the sign (https://goo.gl/maps/xvW37TNL2vL2)

Until WisDOT confirms this - I would hesitate to have the route added.

For those that can see - Chris Lokken drove the short distance of the recenly signed (partially) WIS-318 which spans from I-94 south to US-18. Not all signs are up, but it's clear what the current route is. The album is only visible to his FB Friends though.